From 6a71b0c73d55d0756b358932ba8b10595a77c254 Mon Sep 17 00:00:00 2001
From: hibikiledo <nutsgmuic@gmail.com>
Date: Mon, 8 Aug 2016 13:52:57 +0700
Subject: [PATCH] Add support for Wire library for ESP-01

---
 Adafruit_MCP23017.cpp | 20 +++++++++++++++++---
 Adafruit_MCP23017.h   | 13 ++++++++-----
 2 files changed, 25 insertions(+), 8 deletions(-)

diff --git a/Adafruit_MCP23017.cpp b/Adafruit_MCP23017.cpp
index ad96e8d..9df3810 100644
--- a/Adafruit_MCP23017.cpp
+++ b/Adafruit_MCP23017.cpp
@@ -1,4 +1,4 @@
-/*************************************************** 
+/***************************************************
  This is a library for the MCP23017 i2c port expander
 
  These displays use I2C to communicate, 2 pins are required to
@@ -124,6 +124,22 @@ void Adafruit_MCP23017::begin(uint8_t addr) {
 	writeRegister(MCP23017_IODIRB,0xff);
 }
 
+#ifdef ESP8266
+  void Adafruit_MCP23017::begin(uint8_t addr, uint8_t sda, uint8_t sdc) {
+    if (addr > 7) {
+  		addr = 7;
+  	}
+  	i2caddr = addr;
+
+  	Wire.begin(sda, sdc);
+
+  	// set defaults!
+  	// all inputs on port A and B
+  	writeRegister(MCP23017_IODIRA,0xff);
+  	writeRegister(MCP23017_IODIRB,0xff);
+  }
+#endif
+
 /**
  * Initializes the default MCP23017, with 000 for the configurable part of the address
  */
@@ -287,5 +303,3 @@ uint8_t Adafruit_MCP23017::getLastInterruptPinValue(){
 
 	return MCP23017_INT_ERR;
 }
-
-
diff --git a/Adafruit_MCP23017.h b/Adafruit_MCP23017.h
index ef2ba01..af1fb14 100644
--- a/Adafruit_MCP23017.h
+++ b/Adafruit_MCP23017.h
@@ -1,13 +1,13 @@
-/*************************************************** 
+/***************************************************
   This is a library for the MCP23017 i2c port expander
 
-  These displays use I2C to communicate, 2 pins are required to  
+  These displays use I2C to communicate, 2 pins are required to
   interface
-  Adafruit invests time and resources providing this open source code, 
-  please support Adafruit and open-source hardware by purchasing 
+  Adafruit invests time and resources providing this open source code,
+  please support Adafruit and open-source hardware by purchasing
   products from Adafruit!
 
-  Written by Limor Fried/Ladyada for Adafruit Industries.  
+  Written by Limor Fried/Ladyada for Adafruit Industries.
   BSD license, all text above must be included in any redistribution
  ****************************************************/
 
@@ -24,6 +24,9 @@
 class Adafruit_MCP23017 {
 public:
   void begin(uint8_t addr);
+  #ifdef ESP8266
+    void begin(uint8_t addr, uint8_t sda, uint8_t sdc);
+  #endif
   void begin(void);
 
   void pinMode(uint8_t p, uint8_t d);